Longest Common Prefix Problem Statement

You are given an array ‘ARR’ consisting of ‘N’ strings. Your task is to find the longest common prefix among all these strings. If there is no common prefix, you have to return an empty string.

Input:

The first line of the input contains a single integer, 'T,' denoting the number of test cases.
The first line of each test case contains a single integer ‘N’ denoting the number of strings in the array.
The next line contains ‘N’ space-separated strings denoting the elements of the array ‘ARR’.

Output:

For each test case, print a single string corresponding to the longest common prefix.
Print the output of each test case in a separate line.

Example:

Input:

ARR = [“coding”, ”codezen”, ”codingninja”, ”coders”]

Output:

"cod"

Explanation:

The longest common prefix among all the given strings is “cod” as it is present as a prefix in all strings. Hence, the answer is “cod”.

Constraints:

• 1 <= T <= 10
• 1 <= N <= 3000
• 1 <= |ARR[i]| <= 1000
• Each string consists of only lowercase letters.
• Time limit: 1 sec

Note:

You do not need to print anything. It has already been taken care of. Just implement the given function.